Aerial refueling is a transfer of fuel from one aircraft to another during flight. Typically, a supply aircraft carrying fuel travels along a relatively steady flight path as a receiver aircraft connects via a hose or boom that delivers the fuel. For example, the supply aircraft may be a tanker that flies in a preplanned orbit or flight path, so that a fleet of Unmanned Aerial Vehicles (UAVs) may refuel as needed to extend flight missions. When a UAV is low on fuel, it may return to the tanker by intercepting its flight path and establishing a connection with the tanker for approximately twenty to thirty minutes for refueling.
The receiver aircraft, or UAV, may be equipped with light-sensitive optical sensors that capture image data and enable autopilot of the receiver aircraft. In a typical automated aerial refuel operation, an optical sensor is directed upward to detect the supply aircraft above as the receiver aircraft positions underneath for refueling. Since the receiver aircraft's fueling position tends to be constrained by the supply aircraft's flight path, the position/direction of the optical sensor is also limited during the approach and physical connection of the aircrafts. Sometimes, the supply aircraft's position forces the receiver aircraft's optical sensor to be exposed to the sun at an angle which blinds the optical sensor and renders it inoperable for an extended period of time (e.g., minutes to hours). If the optical sensor used for refueling becomes blinded, the receiver aircraft may be forced to cancel its mission and return to base using its remaining fuel or risk becoming lost.